sturteyant



3 Sheets-Sheet 1.

Patented May 23, 1893.

MILL.

(Hommel.)

` T. L. STURTEVANT.

lwemr mamas L Sr/6740? y ha @n "ings (No Model.) ssneets-sheet 2.4

' T. L. STURTEVANT.

MILL. No. 498,037. Patented May 23, 1893.

(No Model.) 3 Sheets--Slleetv 3.

T. L. STURTEVANT.

Y MILL.

No. 498,037. Patented May 2s, 1893.

me wams percus co. Pnofauruc.. WASHINGTON, n c

Nrrn STATES PATENT OFFICE.

THOMAS L. STURTEVANT, OF FRAMINGHAM, ASSIGNOR TO THE STURTEVANT MILLCOMPANY, OF BOSTON, MASSACHUSETTS.

MILL.

SPECIFICATION forming part of Letters Patent No. 498,037, dated May 23,1893.

Application led August 9, 1892.`

To @ZZ whom t may concern:

Be it known that I, THoMAs L. STURTEVANT, a citizen of the UnitedStates, residing at Framingham, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements inMills, of which the following is a specification.

My invention particularly relates to mills for crushing and grindingores, phosphates, cement and other like hard and refractory materials.It constitutes certain improvements on the attrition mill shown in mypatent, No. 255,550, of March 28, 1882. The mill shown in this patentcomprises a rotary chambered member, and a chamber connected with a feedhopper. The organization and operation are such that the material in acoarse or rocky condition is caused to act upon itself, to reduce itselfinto a comparatively tine or granular condition. Such a mill bothcrushes and grinds the material in a most economical and efficientmanner. It is very powerful and there is little wear and tear on theparts and hence it is durable. Heretofore in running this mill, all thematerial has not been reduced to the desired size, an'd it has beencustomary to transfer the iner reduced material to buhr stones, orsimilar millstones, to nish it or reduce it to the desired powderedform. The coarser material has been conveyed by elevator buckets, orsimilar elevators, to the feed hopper, and has been passed through themill, where it is re-ground to a line granular form, suitable forfinishing in the mill-stones, as above stated.

The object of my present invention is to improve the mill shown in mypatent above referred to in such manner that it shall act moreefficiently to crush and grind the material fed to it, and shall also atone operation reduce the material to the desired degree, thus obviatingthe necessity of re-grinding in buhr stones or of re-conveying thecoarser material to the feed hopper. l therefore employ, in addition tothe rotary chambered member and the chamber connected to the feedhopper, grinding surfaces operated coincidently or simultaneously withthe rotary chambered member, and adapted to act on the reduced materialto grind and pulverize it to the desired degree.

Serial No. 442,558. (No model.)

In the accompanying drawings,-Figure l is a view, partly in longitudinalvertical section, on the line 1*-1 of Fig. 2, and partly in elevation,of a mill embodying my improvements. Fig. 2 is a transverse section, outhe line 2-2 of Fig. l. Fig. 3 illustrates a modification in which oneof the grinding surfaces is rotary and the other stationary. Fig. 4illustrates a further modification of the organization shown in Fig. 3.Fig. 5 is a view in longitudinal vertical section, on the line 5--5 ofFig. 6, of a mill in which the feed hopper is connected at the side tothe crushing and grinding members. Fig. 6 is a transverse section of thesame, on the line 6--6 of Fig. 5, and Fig. 7 is a detail view of afurther modication.

In Figs. l and 2 I have illustrated a mill embodying two rotarychambered members, in combination with grinding surfaces.

Separate shafts A and B, are mounted in standards A', B, supported on asuitable bedplate C. The shafts have suitable bearings a, b, and carrydriving pulleys A2, B2. Each shaft carries at its inner end a flangedhead D, D', to which is secured a cylindrical casing or bushing E, E',the inner ends of which are arranged a sufficient distance apart toaccommodate the stationary central member F. The parts D, E, and D', Eeach constitute a rotary chambered member and they are adapted torevolve in opposite directions. The standards A and B are adjustable onthe bed-plate by hand-wheels Gr, and gearing g, in order that thedistance between the chambered `members may be varied, and a fineradjustment may be obtained by the hand wheels H, and the lock-nuts h.

Material to be ground is fed from the h0pper I, through an opening f,inthe stationary member F, and, in a coarse rocky condition, passes fromthe hopper into the chambered members on each side, which throw itinwardly and cause the rocks to act upon themselves forcibly andpowerfully so that they are crushed and broken up and more or lesspowdered. Soon after the crushing operation has commenced, a portion ofthe finely reduced material adheres to the recessed heads and takes theform indicated by dotted lines at thus forming a protective lining forthe IOO heads or chambered members, and preventing wear except at `theextreme inner beveled edges of the cylinders or bushings E, E.

In the mill shown in my patent above referred to, the reduced materialwas discharged through a screen, and this screen was subject to more orless wear, and it was necessary from time to time to renew it. I nowomitthe screen, and, as shown in Fig. l, surround each chambered member with.a stone or grinder K, which may be of buhr stone, or it may be acomposite stone comprising small irregular lumps of emery and a bindingmaterial. So far as the scope of my invention extends, however, anysuitable grinding material may be employed, but I prefer those*specifically mentioned.

The central stationary member F, has an opening F', extending through itand communicating With the passage f, leading to the feedhopper, and theouter sides 'or edges of the stationary member are in suitableproximity'to the grinders K, t0 reduce the grannlar material passingfrom the chambered members tc the desired degree. Any suitable exit maybe employed for the powdered material.

I have shown the working parts of the4 mill surrounded by a casing L,and I preferably employ a discharge opening L', at the bottom thereof;out readily from between the grinders, v is guided by the casing to thedischargespout or opening L', from Which it may be' delivered to asuitable receptacle.

The grinders K, as above explained, are carried bythe rotary members E,E', whichl revolve iiropposite directions, and the grinding surfaces maybe adjusted by means of the hand-wheels Gand H, in the manner beforeexplained, to regulate the size or tineness ofthe material dischargedfrom 'the machine.

In Fig. 3 I have indicated a slight modification. be stationary, WhiletheV other rotates. The grinder-M, on the left hand side', hasa'fcentral chamber m, which communicates with an opening m', at the tcp,connected with the feed hopper I. The rotary chamber-ed lmember E, andthe grinder K, are similar in all respects to those indicatedat E andK', iny

Fig. 1. Motion may be imparted to the shaft Ain any suitable Way. Thechambered members and grinders are surrounded by a suitable casing L,and the material is discharged through an opening L', in the casing.v

In Fig. 4 the arrangement is substantially the same except that thechamber m, in the* stationary member M, is somewhatv larger indiameterthan the chamber in the rotary member.

The mill shown in Fig.- 5 is simpler and less powerful than that shownin Fig. 1. The

chambers are formed in the grinders N, N', and these are surrounded by asuitable cas- 1ng L. The grinder N is stationary, and may All thereduced material passingy As there shown, one member mayf be cemented inthe casing, as indicated. The grinder N is cemented to a flanged frameO, secured to the shaft A, which has bearings 0, in suitable standardsor brackets P. One end of the shaft is provided with an adjustinghand-wheel R, carried by a screw r, having ahead r', between which andthe shaft are interposed anti-friction balls r2. The screw passesthrough a head r3, in acylinder r4, and this cylinder is surrounded by aspiral spring T5, within a casing r6. This construction affords adesirable arrangement for adjusting .the grinding surfaces.

The hopperI is provided with an adjustable feed-spout I', of well knownconstruction "andthe material to be ground' is delivered from the spoutto archute l2, communicating with another chute I3, which delivers the.coarse or rocky material through an opening@ to the chambers of thegrinders.

A similar mill to that just described may be constructed with afeed-opening at the top,

as indicatedin Fig. 7; This figure shows'th-e other parts of themechanism substantially the-same as those indicated in Fig. 5.

.- A mill constructed in accordance withmy einve'ntionA possesses manyadvantages.A Itv grinds fine at one operation. There areno tailings tobe returned foi1 re-grindin'g, and screening is dispensed with.y Noauxiliary y'Ii'nishin g machineis necessary. The mill will iact'o'neither wet or dry material, and isnot easily clogged. All thel partsfofthemach-ine are'- strong and durable, and, as the forcel required toreducey the material is mainly exp`ended by the largerrocks strikingagainstthemselves, andk breaking up into granular form', the strainontheWorkingeparts 1s materially reduced, and for this reason themill runsmore easily, works more-efficiently', andv lasts much longer Withoutrepair.V

I claim as my inven'tion-A 1. A crushingiand grinding -mill comprisingia chamber to which'the material to be re-- duced is`fed,za'rotarycup-shaped member having an en'd piecefand a'deep cas-ing. ory

-bushing proj ectingat substantially-rightanigles from-the end piece, anannular grinder surrounding the fouterend of the'lcup-shaped casing;land' connected thereto to revolve therewith, and anopposinggrinder-adjacent to said rotary-grinder.

2. A crushing and grinding mill comprising a chamber to which'y the'material'to bereduced is fed, a cup-shapedmember revolving kabout ahorizontal axis byJ which .the-coarse' material is vmade-to actupon'itself to reduce jitself to a granular form and Which comprises aclosed'end with a'cylindrical casing projecting at right anglestherefrom and form# ing a chamber having a'smooth interior sur-Fface',an annular grinder surrounding the outer ,end of the chamberedmember, another an- `inular grinder in close proximity thereto andmeansffor adjusting the chambered'member' `and one grinder relatively tothe other grinder'.

3. A crushing and grinding mill comprising IOC IIO

a chamber to which the material to be reduced is fed, a rotarycup-shaped member comprising an end piece, and a cylindrical bushing orcasing projecting at right angles therefrom and greater in length thanonehalf the diameter of the head, and adjustable grinding memberssurrounding the rotary chambered member to further reduce the materialbefore it is discharged from the inachine.

4. The combination of a central stationary chambered member, a feedhopper communicating therewith, a rotary cup-shaped member on each sideof the stationary member, each comprising a head piece, provided with acylindrical bushing projecting at rightangles from the head piece, meansfor rotating the chambered members in opposite directions, and grindershaving parallel grinding surfaces surrounding the chambered members,substantially as set forth.

5. The combination of a central, stationary grinder having a centralchamber, a feed hopper communicating with an opening in the centralgrinder which leads to the central chamber thereof, a rotary chamberedmember on each side of the'stationary grinder, each comprising anend-piece and a cylindrical bushing projecting at right angles therefrommeans for rotating the chambered members in opposite directions, and anannular grinder on each side of the cent-ral grinder and surrounding thechambered members, substantially as set forth.

6. The combination of a chambered meniber to which the material to beground is fed, a rotary chambered member communicating therewith, andcomprising an end-piece and a cylindrical bushing projecting at rightangles therefrom grinders surrounding the r0- tary chambered membercomposed of small, irregular lumps of einery and a binding ma terial,means for rotating the rotary chambered member and one of the grinders,a casing surrounding the working parts ofthe apparatus and provided witha discharge opening through which the finely reduced material isdelivered.

In testimony whereof I have hereunto subscribed my naine.

THOMAS L. STURTEVANT.

Witnesses:

EDWARD H. MASON, W. H. ELLIS.

